Abstract: To solve calculable problem of the reliability of fibre channel (FC) interconnection, based on basic FC interconnection model, a task based analysis method of system reliability was proposed, a reliability model of FC interconnection system was developed and the matrix of system reliability was used to describe reliability model. To three basic topologies of FC: point-to-point, arbitrated loop and Fabric, expressions were directly defined by reliability model. Based on combination topology of FC, the bridge-port in reliability model was defined, a reliability model of combination topology with bridge-port was developed. To a combination topology of Fabirc and arbitrated loop, an illustration of modeling avionics of FC network was also presented. By analysing the influence of bridge-port in task route, it is showed that bridge-port influences reliability of FC interconnection system most. The reliability model of task based has a directive effect on both task division and topology selection in the phase of avionics system design.